The statement read: "The governor of Bali, Mangku Pastika, wishes to share a message with all of us: 'There is an indication of an attack to Bali tonight' ... please don't panic, but put your security system to full alert."

However, Putu Suardika, the head of public relations at the Bali governor's office, denied that Pastika had made such a statement.

"No, he never said that, either in writing or verbally," Suardika told Reuters. "We never put out any warning, either written or spoken.

"Of course we in Bali, because we have had two bombs in the past, have to remain on alert."

Attacks on Bali in 2002 and 2005 killed more than 200 people. In July, suicide bombers attacked the Ritz-Carlton and JW Marriott hotels in Jakarta, killing seven people and themselves and wounding 53 others.

The Indonesian government said the al-Qaida-linked group Jemaah Islamiyah, led by Noordin Mohammed Top, carried out the attacks. Top was killed by Indonesian police in September.

On its website, the Foreign Office – which also cited the warning from the Bali tourism board – said there was a high threat from terrorism throughout Indonesia.

"Terrorist groups continue to plan attacks and have the capacity and intent to carry out these attacks at any time and any where in the country," it said.

"Attacks could be indiscriminate, including in places frequented by expatriates and foreign travellers."

Police in Bali played down the threat of an imminent attack. Gde Sugianyar, a police spokesman, said officers were not aware of a threat and always tried to ensure security was as tight as possible.

"There is no initial indication so far. Everything is running well and secure in Bali," he told Reuters.

"For us, we don't consider whether there is any threat or not, but we have been preparing security for the New Year's Eve to be as tight as it can."